KA24DE sluggish/weak start - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

Rambo slice · 10-22-2023, 01:52 PM

Bought this car that was daily driven. Previous owner said it started to give him starting issues until it eventually stopped starting completely, he would jump it until that didnt work anymore then parked it for a year(he knew nothing mechanically). I installed brand new starter and battery. I can turn the engine with a breaker bar, it has oil, when i look in the engine the tops of the cylinders are black, has new starter and battery. Tried push starting it but when I release the clutch pedal rear end just locks up. Is it a timing issue? compression issue? It's frustratingly beyond my knowledge...

1st vid of weak start
https://youtu.be/cQGraoorXVc

same vid with spark plugs removed
https://youtube.com/shorts/gVna1dc3W3A?feature=share

If anyone has dealt with this before and knows what the problem is your help would be greatly appreciated!

wezurii · 10-22-2023, 11:34 PM

Compression test it
Are all the grounds connected ?
Is the wiring okay ?
Are all the connectors connected
Does it get enough power on the starter ?

Sounds like it either loses compression or doesn't get enough power to start.

Thursday7 · 10-23-2023, 08:10 AM

Test for spark and compression. Fuel as well, however you prefer to do this. If you have all of those, check your base timing.

Set Cyl 1 to TDC on compression stroke. Pop the valve cover and look down the timing chain passage to where the distributor enters the head. There is a timing mark and a dot (like a divet) that need to line up. One is on the distributor gear shaft and the other is on the body of the distributor. If they are not lined up, pull the distributor and reinstall so that they do. This may require a few tries. You can also verify that the rotor contact is perfectly lined up with Cyl 1 on the cap. I prefer to use the timing mark on the distributor itself as it is more concrete and requires less guess work, even if it does mean pulling the valve cover.

ch1873857 · 10-23-2023, 04:45 PM

How many miles. Do nothing else until you comp test. If low, put an ounce or so of oil down the plug well and repeat. If comp jumps up, you have bad rings. Based on what you said it's likely rings.

Rambo slice · 10-23-2023, 08:12 PM

Quote:

Originally Posted by ch1873857

How many miles. Do nothing else until you comp test. If low, put an ounce or so of oil down the plug well and repeat. If comp jumps up, you have bad rings. Based on what you said it's likely rings.

Ok ill do this tomorrow

Rambo slice · 10-23-2023, 08:16 PM

Quote:

Originally Posted by Thursday7

Test for spark and compression. Fuel as well, however you prefer to do this. If you have all of those, check your base timing.

Set Cyl 1 to TDC on compression stroke. Pop the valve cover and look down the timing chain passage to where the distributor enters the head. There is a timing mark and a dot (like a divet) that need to line up. One is on the distributor gear shaft and the other is on the body of the distributor. If they are not lined up, pull the distributor and reinstall so that they do. This may require a few tries. You can also verify that the rotor contact is perfectly lined up with Cyl 1 on the cap. I prefer to use the timing mark on the distributor itself as it is more concrete and requires less guess work, even if it does mean pulling the valve cover.

I dont see how spark or fuel would make it seem so sluggish

Thursday7 · 10-24-2023, 06:38 AM

Quote:

Originally Posted by Rambo slice

I dont see how spark or fuel would make it seem so sluggish

Given the below, I assumed the car doesn't start at all... Either way, weak spark or a fucked up fuel system will make any engine run less than stellar.

Quote:

Originally Posted by Rambo slice

until it eventually stopped starting completely, he would jump it until that didnt work anymore then parked it for a year(he knew nothing mechanically). I installed brand new starter and battery. I can turn the engine with a breaker bar, it has oil, when i look in the engine the tops of the cylinders are black, has new starter and battery. Tried push starting it but when I release the clutch pedal rear end just locks up.

AKADriver · 10-26-2023, 02:56 PM

That intake manifold bolt that's right in the middle of the video is supposed to be connected directly to the battery with the heavy gauge ground cable. It's one big cable that goes from battery to the chassis right below the battery tray to that bolt. Without that the starter is relying on a much weaker ground path, unless you relocated the battery and added a new dedicated heavy gauge engine ground somewhere.

When it makes the high pitched "whizz" that sounds like the starter bendix isn't fully extending so it's spinning the motor but not making flywheel contact.

It's a new starter but it's not an OEM starter, there's a chance the starter could also be a POS. Lots of aftermarket and reman starters and alternators are defective. My car has a reman starter and it works but it kinda... sucks and cranks slowly even though my battery is good and engine is healthy.

Rambo slice · 10-26-2023, 04:12 PM

Quote:

Originally Posted by AKADriver

That intake manifold bolt that's right in the middle of the video is supposed to be connected directly to the battery with the heavy gauge ground cable. It's one big cable that goes from battery to the chassis right below the battery tray to that bolt. Without that the starter is relying on a much weaker ground path, unless you relocated the battery and added a new dedicated heavy gauge engine ground somewhere.

The battery was relocated by the owner before the kid i bought it from. Its not great but it is chassis grounded in the trunk.

AKADriver · 10-26-2023, 09:29 PM

I think you may still need a better engine ground. As it is it's kind of relying on the small ground strap on the firewall as its main engine ground. This could be where the problem started for the PO and why it would start from a jump.

Can't hurt to try, grab a jumper cable and just whack it from the motor to a big chassis bolt and see if that helps.

10-22-2023, 01:52 PM	#1
Rambo slice Zilvia Addict Join Date: Jul 2011 Location: Eastern NC Posts: 615 Trader Rating: (7) Feedback Score: 7 reviews	KA24DE sluggish/weak start Bought this car that was daily driven. Previous owner said it started to give him starting issues until it eventually stopped starting completely, he would jump it until that didnt work anymore then parked it for a year(he knew nothing mechanically). I installed brand new starter and battery. I can turn the engine with a breaker bar, it has oil, when i look in the engine the tops of the cylinders are black, has new starter and battery. Tried push starting it but when I release the clutch pedal rear end just locks up. Is it a timing issue? compression issue? It's frustratingly beyond my knowledge... 1st vid of weak start https://youtu.be/cQGraoorXVc same vid with spark plugs removed https://youtube.com/shorts/gVna1dc3W3A?feature=share If anyone has dealt with this before and knows what the problem is your help would be greatly appreciated!

10-22-2023, 11:34 PM	#2
wezurii Leaky Injector Join Date: Jun 2014 Location: Mars Age: 34 Posts: 130 Trader Rating: (0) Feedback Score: 0 reviews	Compression test it Are all the grounds connected ? Is the wiring okay ? Are all the connectors connected Does it get enough power on the starter ? Sounds like it either loses compression or doesn't get enough power to start.

10-23-2023, 08:10 AM	#3
Thursday7 Zilvia Addict Join Date: Jul 2011 Location: PA Posts: 800 Trader Rating: (8) Feedback Score: 8 reviews	Test for spark and compression. Fuel as well, however you prefer to do this. If you have all of those, check your base timing. Set Cyl 1 to TDC on compression stroke. Pop the valve cover and look down the timing chain passage to where the distributor enters the head. There is a timing mark and a dot (like a divet) that need to line up. One is on the distributor gear shaft and the other is on the body of the distributor. If they are not lined up, pull the distributor and reinstall so that they do. This may require a few tries. You can also verify that the rotor contact is perfectly lined up with Cyl 1 on the cap. I prefer to use the timing mark on the distributor itself as it is more concrete and requires less guess work, even if it does mean pulling the valve cover.

10-23-2023, 04:45 PM	#4
ch1873857 Nissanaholic! Join Date: Sep 2003 Location: Andrews Air Force Base Posts: 1,906 Trader Rating: (1) Feedback Score: 1 reviews	How many miles. Do nothing else until you comp test. If low, put an ounce or so of oil down the plug well and repeat. If comp jumps up, you have bad rings. Based on what you said it's likely rings.

10-26-2023, 02:56 PM	#8
AKADriver Post Whore! Join Date: May 2002 Location: Springfield, VA Age: 43 Posts: 3,517 Trader Rating: (1) Feedback Score: 1 reviews	That intake manifold bolt that's right in the middle of the video is supposed to be connected directly to the battery with the heavy gauge ground cable. It's one big cable that goes from battery to the chassis right below the battery tray to that bolt. Without that the starter is relying on a much weaker ground path, unless you relocated the battery and added a new dedicated heavy gauge engine ground somewhere. When it makes the high pitched "whizz" that sounds like the starter bendix isn't fully extending so it's spinning the motor but not making flywheel contact. It's a new starter but it's not an OEM starter, there's a chance the starter could also be a POS. Lots of aftermarket and reman starters and alternators are defective. My car has a reman starter and it works but it kinda... sucks and cranks slowly even though my battery is good and engine is healthy.

10-26-2023, 09:29 PM	#10
AKADriver Post Whore! Join Date: May 2002 Location: Springfield, VA Age: 43 Posts: 3,517 Trader Rating: (1) Feedback Score: 1 reviews	I think you may still need a better engine ground. As it is it's kind of relying on the small ground strap on the firewall as its main engine ground. This could be where the problem started for the PO and why it would start from a jump. Can't hurt to try, grab a jumper cable and just whack it from the motor to a big chassis bolt and see if that helps.